The candidate is an experienced academic clinician, trained in pediatric pulmonology and sleep medicine, who plans to re-train in clinical epidemiology. This award is expected to help transition the candidate's focus from physiological testing to clinical epidemiology. The candidate's career goals are to develop an independent research career concentrating on the identification, diagnosis, treatment, and outcomes assessment of obstructive sleep apnea (OSA) in children. The specific objective of the research proposal is the rigorous systematic assessment (reliability, accuracy, and cost effectiveness) of a diagnostic strategy for OSA in children that relies on clinical predictors and simplified home (unattended) monitoring. The candidate proposes a five-year training program with an experienced team of faculty mentors from strong research departments. This plan describes activities (advanced degree coursework, independent study, patient based clinical research) focused on developing skills in clinical epidemiology with immediate applications to the diagnosis of sleep disordered breathing in children. Specific activities in the plan include research training in statistical methods, experience with data analysis in large databases, supervised experience in preparation of grant proposals for individual research support, and training in the responsible conduct of research. The proposed research addresses important knowledge gaps about diagnostic testing for OSA in children and provides important new data for rational and cost-effective application of technology to an under-recognized health condition of children. Furthermore, clarification of the role of diagnostic testing and outcome assessment in pediatric OSA will be crucial for future randomized controlled trials of treatment efficacy; mechanistic studies, and population based studies of pediatric sleep disorder breathing. Finally, the proposal will provide a key training opportunity to foster the candidate's career development as a clinical epidemiologist with a commitment to patient based research in pediatric sleep medicine and pulmonology.